07 Presentation Workshop Delft Lesny Final Comparaison EC7 Din1054

8/13/2019 07 Presentation Workshop Delft Lesny Final Comparaison EC7 Din1054

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Implementation of Eurocode 7 in Germany

and Consequences for Practical Design

Kerstin Lesny

University of DuisburgEssenInstitute of Geotec!nics

"afety Concepts and Calibration of Partial #actors inEuropean and $ort! %merican Codes of Practice

&or's!op ()*++ , )+*+-* -)++ Delft University of .ec!nology


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0istory of Geotec!nical Design in Germany

Geotechnical design in Germany originally -ased on a glo-al safetyconcept with an o+erall factor of safety

.afety concept defined in DIN '%/0 1'2734 with reference to +arious

design codes 1e&g& DIN 0%'7 for the -earing resistance4

Definition of global factor1 2 3 45E min

R5 E 6 deterministic +alues5 named as cal E5 cal R

Glo-al factors

e&g& -earing resistance failure 86)5%

e&g& pile -earing capacity 86)5%

for load case '

Distinction of three load cases determining the le+el of safety

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to -e deri+ed directly from the results of soil mechanical tests

-asic +alue is the reduced arithmetic a+erage from n tests

appropriate additions or deductions to consider the heterogeinity of theground5 uncertainties during soil sampling and testing

e&g& reduction of shear strength paramaters according to E23 of E9*

E9*7 Recommendations of the Committee for "aterfront .tructures

Definition of deterministic values of soil parameters6acc* to E%U1

$5'

cccal uu

'5'

tantancal

$5'

cccal

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deterministic +alues R5 E 1cal R5 cal E4 : characteristic +alues E#5 R#

"ith DIN '%/0 1)%%$4 ;.D first has -een introduced in Germanyparallel to the de+elopment of Eurocode 75 re+ised in )%%/

Resistance factors Rderi+ed from glo-al factors assumingtypical partial factors for effects of actions Eailure of structures or structural components -y failure of the structure or theground5 e&g& sliding5 -earing resistance failure5 failure of piles5 retaining structures5

etc&= partial factors on characteristic effects of actions and resistances

G: +CGlo-al failure of the ground5 e&g& slope failure= partial factors on actions and onshear strength parameters

G: -Displacements and rotations= partial factors are equal to one



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Concept of load cases

< according to DI$ +)=> 6+?7@1

;C' Permanent loads and regularly occuring +aria-le loads

permanent design conditions

;C) plus irregularly occuring +aria-le loads and loads that only occurduring construction

transient design conditions

;C$ plus e!traordinary loads

according to DI$ +)=> 6-))=

Concept of load cases maintained5 -ut they now depend on com-inationsof actions and safety classes



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Combinations of actions$ormal combination C%+1 Permanent and +aria-le loads

4are combination C%-1 Rare loads or loads occuring only once

EAtraordinary combination C%(1 E!traordinary actions occuring at the sametime5 i&e& catastrophic incidents

"afety classes"afety class "C+1 Normal conditions during the lifetime of the structure

"afety class "C-1 Conditions during construction or maintenance of a structure

"afety class "C(1 .ingular or pro-a-ly ne+er occuring conditions during thelifetime of the structure

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Implementation of Eurocode 7

/riginal timetable for t!e implementation of Eurocode 7 inGermany as DI$ E$ +??7+1

@empfert 1)%%24

DI$ E$ +??7+ Bit! $%

revised DI$ +)=>



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DIN EN '227')%%2

.chuppener A Ruppert 1)%%74

DIN '%/0)%%/ as Bthe German way to Eurocode 7 designed to maintain thespecial e!periences included in German design codes

DIN '%/0)%%/ had to -e completely re+ised due to o+erlapping regulations

notadopteddesign

approachesand

informati+eanne!es

ointregulations

e&g&limit states5

partialfactors5

geotechnicalcategories

particularGerman

e!periencese&g& acc& -ase

pressures5pile resistances

DIN '%/0)%%/

Eurocode 7 vs* DI$ +)=>1-))=)+

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Current situation

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$ormen0andbuc!6Codes 0andboo'

"ummary of t!e t!ree codes

pu-lished in ay )%''

>or a -etter reada-ility of thethree codes1-)+)+-

4ed1 partial factors acc* to DI$ +)=>1-))=)+

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$eB 4egulations for Geotec!nical Design

Partial factors for resistancesaccording to DIN '%/0)%'%') a-stract

;lac'1 factors acc* toDI$ +)=>1-)+)+-

4ed1 factors acc* toDI$ +)=>1-))=)+

4esistance "ymbolDesign situation

;"P

6LC+

;".

6LC-

;"%

6LC(".4 and GE/-1 Limit state of failiure according tostructures components and foundation ground

"oil resistances

Passi+e earth pressure

and -earing resistance

R5e5 R5++>)

6+>)

+()

6+()

+-)

6+-).liding resistance R5h

++)6++)

++)6++)

++)6++)

Pile resistance from static and dynamic pile load tests

-ase resistance -++)

6+-)++)

6+-)++)

6+-)

shaft resistance1pressure4

s++)

6+-)++)

6+-)++)

6+-)

total resistance1pressure4

t++)

6+-)++)

6+-)++)

6+-)

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Eurocode 7 Design EAamples , EAample +

.quare pad foundation

Characteristic loads

G+5#6 '%%% #NGh5#6 %J+5#6 7/% #NJh5#6 /%% #Nc 6 )/ #NmK

.oil -oulder clay

Detailsfi+e .P, tests5 water contents and inde! tests-ul# weight density )'&0 #NmKground water le+el '&% m -elow ground le+el

Consequences for Practical Design , EAamples

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Comparison of design approac!es Bit! German design Bit!inD%-

"pecific features in t!e calculation1

Design %pproac! + 6combination + and - and (

partial factors according to DIN EN '227')%%2%25 ,a-les 9&$&' to 9$&$

Design %pproac! -

partial factors according to DIN '%/0)%'%')5 ,a-les 9&)&' to 9)&$

Design met!od for bearing resistance according to DI$ >)+71-))@)(


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C!aracteristic soil parameters1

*ndrained conditions cu#6$%% #NmL5 Mu#6%

Drained conditions cO#6'/ #NmL5 M#6$%

Derived as eAperience values acc* to recommendations in

E%U 6-))>


DIN EN I.Q ))073$)%%/%0 on .P, testing does not include anycorrelations to shear parameters=

arious correlations a+aila-le in the literature ha+e -een e!amined=

>inally e!perience +alues found to -e reasona-le

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4esults of t!e bearing resistance calculation

*ndrained conditionsPad width acc& to D9) ) minimally larger 1)5?2 m4 than acc& to D9' and D9$

Drained conditionsPad width acc& to D9) much larger 10532 m4 than acc& to D9' and D9$

Pad Bidt! D%+6Comb* + D%+6Comb* - D%- D%(

F SmT1*ndrained condition4

)5/$ )53$ -F? )5/$

F SmT1Drained condition4 $500 $50/ >@? $500

86RdNd or R#N#1undrained condition4

'5%'0 '5%)' '5??% '5%'0

86RdNd or R#N#1drained condition4

'5%'7 '5%)7 )5'%? '5%'7


DI$ +)=> 6+?7@1

min 3 -) 6LC+

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Eurocode 7 Design EAamples , EAample @

Fored piles5 D 6 0/% mm5 a 6 ) m

Characteristic loads for each pileG#6 $%% #N

J#6'/% #N

.oilPleistocene fine and medium sand

co+ered -y Holocene layers of loose sand5

soft clay5 and peat

Details

' CP, at a distance of /m from the -oring

performed and e+aluated acc& to DIN 0%20')%%)




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Determination of soil parametersCP, test used for the determination of pile length acc& to DIN '%/0)%'%')and E9P 1)%%74

qc

1U4 6/%5$0V)523/U

0 4 8 12 16 20

Spitzenwiderstand qc[MPa]

-30

-20

-10

0

Tiefez[m]


;inear regression



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.oil layers -etween % and W'/ m assumed to -e not-earing

Design pile length -elow W'/ m

9+erage +alue of cone resistance for this depthrange

qc 3 +++F> $5mH

,a-le cone resistance +s& depth from linear regression


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Tiefe z[m]qc [MN/m]

15,5 -4,3825

16 -2,9

16,5 -1,4175

17 0,065

17,5 1,5475

18 3,0318,5 4,5125

19 5,995

19,5 7,4775

20 8,96

20,5 10,4425

21 11,925

21,5 13,4075

22 14,89

22,5 16,3725

23 17,855

23,5 19,3375

24 20,82

24,5 22,3025

25 23,785

25,5 25,2675

26 26,75

depth z[m]


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Comparison of design approac!es Bit! German design Bit!inD%-

"pecific features in t!e calculation1

Calculation according to D%+ 6Combination + and D%-

D%+ 6Combination - and D%( were not included in this calculation

,he applied calculation model acc& to DIN '%/0)%'%') and E9P 1)%%74is -ased on empirical +alues for the pile resistances=

Partial factors can only -e applied on resultant resistance 1i&e& R45material factors cannot -e applied

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07 Presentation Workshop Delft Lesny Final Comparaison EC7 Din1054

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